Boiler construction



Feb. 9,A 1937. J. P. BADENHAUSEN BOLLER CONSTRUCTION Filed Sept. 5, 19353 Sheets-Sheet 1 INvEN-ro/v zz. y

'il if" WITNESS HTTO RNEf Fell)B 9, 1937. .1. P. BADENHAUSEN BoILERCONSTRUCTION Filed Sept. 5, 1935A 5 Sheets-Sheet 2 Patented Feb. 9, 1937UNITED Is'r-.frias lPA'rEN'rA OFFICE BOILER CONSTRUCTION John PhillipsBadenhausen, Philadelphia, Pa., assigner of one-half to Day andZimmermann, Incorporated, Philadelphia, Pa., .a corporation of MarylandApplication September 5, 41935, Serial No. 39,254 claims.- (cL' 12e-47s)like, it has been rather common to try to utilize the steam generatingdesigns of ordinary boiler construction and to add thereto provisionsfor u cooling the walls of the combustion chamber and for dischargingthe steam and hot water from the cooling walls-directly 'into thecirculatory system of the steam generating section; the resuit ofthishas been to make the completed structure increasingly higher, as thecapacity of the boiler was increased, thereby making the boilers occupytoo much valuable space. There has not beenwery much of an endeavormanifested to completely re-design a steam generator for use with suchfuels without reference to standard boilers, designed to burn ordinarycoal.

The object of the present invention is to simplify the design of boilersusing finely divided fuels, by providing thesteam-generating sectionthereof,l with. merely one large steam and water drum, withtwo-relatively small headers and with as few water tubesas possiblelconnecting said drum and headers.

A further object of this invention is to provide a construction lwherebythe gases of combustion,

reaching the superheater, are of relatively higher temperature than theyare in boilers, as heretofore constructed, thereby enabling me to reducethe heating' surfaces of the superheater and with o' that the cost ofthe same.

A further object of this invention is to provide a construction whichwill make the over-all height and also the depth of theboilerconsiderably less than the corresponding dimensions of a boiler ofequal capacityas constructed up tothe present time. l

A further object of this invention is to make possible the placement ofan air heater or economizer, or both, withinthe space heretoforeoccupied bythe large mud drum and the large bank of downcomer tubesconnecting the mud drum with the steam-and-water drum with which boilersof this type have been heretofore provided.

A further object of this invention isvto utilize an economizer as anactive part of the main heating surfaces of the boiler therebysubstituting the verycompact arrangement of economizer tubes with itsf/great` heat absorptive proper-v ties for the relatively widely spacedaggregations of tubes heretofore employed, thereby utilizing v comers.

the greater heat-absorptionl properties of the economizer, over that ofthe ordinary boiler tubes in the steam-generating section.

The heating surfaces of the ordinary boiler or steam generator isdivided into upcomers and downcomers. Since water in the heatingsurfaces, absorbing heat, will tend to rise naturally and since theheating 'of the upcomer tubes in- `creases the upward rise of the watertherein, it

follows that the heating of the downcomers tends to retard the downwardflow in the down- This, therefore, results in an unequal circulation ofthe water,.which will be faster in the upcomers than in the downcomersand this may result in the failure of the water to move in certain ofthe tubes with a consequent overheating `and sagging of some of thetubes. 'I'he' natural ow ofthe water in the tubes should always beupward and the downcomers should be subjected, if possible, to a minimumexposure to the gas flow, or to a minimum heating surface in the boilergases. The greater the heat of the water in the boiler the faster willbe the velocity of the circulation in the upcomers. All of this tends todisturb the proper circulation of water within the steam generatingsection.

A further objectv of the present invention is, therefore, to provide aconstruction for the free,

` unimpeded circulation of the water in the steamgenerating section ofthe boiler and in the water walls, from the bottom of the structuretoward' the steam-and-water drum, by' shielding the downcomers as muchas possible from the radiant heat of the combustion chamber and bysupplying the coolest water in the boiler to the steam ygeneratingsection and to the wall cooling at points near the bottom ofthe boilerstructure, whence it freely circulates upwardly throughout the tubes. h

Other objects of my invention will appear in the specication and claimsbelow. A,

In the drawings forming a part of this speciiication and in which likereference characters drum, the intermediate header, the lower header andthe upper header of the cooling section of a side wall of a boiler, toclearly indicate the connetions of the banks of tubes thereto.

Referring now particularly to Fig. 1, the boiler comprises asteam-and-water drum A, a relatively small intermediate header B and arelatively small lower header C. The intermediate header B is connectedto the steam-and-water drum A by two banks D and E of tubes and thesteam-and-water drum A is. connected with the lower header C by a bank Fof downcomer tubes, which is entirely shielded from the radiant heat ofthe combustion chamber by the baille G and the rear wall H of thefurnace.

The intermediate header B and the lower header C are connected by arelatively small double bank I of steam-generator tubes.

It will thus be seen that the circulation of the water in thesteam-generating section of the boiler is continually upwardly in thebanks D, E and in the bank I of tubes, the downcomer bank F beingcompletely shielded from the radiant heat of the combustion chamber, andlocated in that portion of the boiler where the gases of combustion arecomparatively cool.

Only one of the side walls J is shown in the drawings, it beingunderstood that both side walls of the boiler are substantially alike.Each is water-cooled bya bank K of tubes extending vertically and closeto the wall, the opposite ends of the bank being connected respectivelyto the upper side-wall header L and to the lower sidewall header M. Thelower header M is connected to the lower boiler header C by a set oftubesm outside of the side wall J, by which they are shielded from theradiant heat of the combustion chamber. Each of the upper side wallheaders L is connected by a bank of tubes N with the steam-and-waterdrum A at the end of the drum beyond1 and beside the banks D and E ofthe generator section of the boiler, and on the inner surface of theside wall which is water cooled thereby.

The rear wall H and the bafe G are water cooled by two banks O and P ofrisers extending upwardly adjacent thereto and extending from the lowerheader C directly to the steam-andwater drum A, the banks passingthrough the upper portion of the bafe G. The bank O lies behind but onthe outer side of the wall H, but

passes through it at the top thereof and lies on the inner side of thebaille G, and the bank P lies on the inner side of the wall H and on theinner side of the baille G. Both said banks are thus exposed to theradiant heat of the combustion chamber.

The economizer Q which may be of standard construction, is preferablywithin the boiler beneath the steam-and-water drum A. It occupies thespace usually occupied by the large bank of downcomer tubes heretoforeemployed in a water circulating type of steam generator. Gases ofcombustion, after passing from the combustion chamber and over the banksof steam-generating tubes D, Ey are conducted into the upper end of theeconomizer Q which presents a much greater capacity for absorbing theheat from the gases than the loose congregation of steam generatingtubes heretofore utilized in boiler construction. The lower end of theeconomizer communicates directly with the lower end of the air heater R(of usual construction) in which the air forced into the upper end ofthe heater R is heated and conveyed therefrom by the air conduit S tothe pulverized fuel burners T.

Feed water is introduced into the lower end of the economizer by thepipe U and the heated' steaming water therefrom is delivered bya bank Vof tubes communicating with the underside of the steam-and-water drum A,whence it passes to the bank F of downcomers communicating respectivelywith the lower header C, the lowest point in the generating section, thelowest point of the banks O and P of risers, and to the lowest headers Mof the side wall banks K through tubes m.

It is here to be observed that this arrangement of the banks ofsteam-generator and wall cooling tubes is of particular advantage inenabling me to locate and install the superheater W in substantially thehottest part of the boiler immediately over the staggered small bank Iof generator tubes. This enables me to reduce to a minimum, the heatingsurface of the tubes of the superheater, and to thus substantiallyreduce the cost of construction. The superheater W may be connected tothe steam space of the steam-and-water drum A by a pipe X, and thesuperheated steam may be delivered from the superheater by the pipe Y.

Referring now to the development of the surfaces of the steam-and-waterdrum A, the head# ers B, C and the side wall upper header L as shown inFig. 4, it will be seen that by staggering the upper ends of the banks Dand E of the steam-generating section, where they are connected to thesteam-and-water drum A greater space may be provided between thecircumferential rows of holes in the steam-and-water drums than isprovided in ordinary steam-generator construction, thereby substantiallyincreasing the ligature strength of the drum to adapt it to the highpressures now availed of in boilers of this type, and withoutincreasinga the thickness of the wall of said drum.

The tubes of the various banks of tubes are designated in Fig. 4 bylower case letters corresponding to the capital letters heretoforeemployed in referring to the banks as a whole. The points of attachmentof the tubes to the steamand-water drum A, to the intermediate header B,the lower header C and to the top side wall header M are clearlyindicated. The tubes d1 to d4, of bank D are disposed in a row extendingcircumferentially of the drum A, connect, and are connected to theintermediate header B at d1, d2, d3, d4 respectively. The tubes el, e2,e3, e4, of the bank E are connected to the intermediate header B in astaggered relationship at e1, e2, e3, e4 respectively. The ligaturestrength of the small header B may be maintained by increasing thethickness of its wall.

The banks O and P of riser tubes o and p of the steam generator extendupwardly from the lower header C to the steam-andwater drum A areindicated as the pipes o and p in Fig. 4. They are preferably in astaggered relationship with respect to the drum A and with respect tothe header C. The position of the bank F of shielded downcomer pipes fis indicated clearly in the developments of the surface of the drum Aand lower header C. On the drum A (Fig. 4) is also indicated thepositions of the pipes v1, 112, leading from the economizer Q. In Fig. 4is also indicated the position of the pipes i1 and i2 of the bank I,extending from the header B to the header C. 'I'he position of the risertubes o alternate with the downcomer tubes`F back of the wall H ber.

and are preferably staggered in their connections with the header C anddrum A.

At the ends of the drum A is a row of tubes n1 to n comprising the bankN and indicated on the development of the drum A and of the header L,and the ligature strength of the drum A is thus retained.

It will be readily seen that the top wall Z of the combustion chamberiswater-cooled by the upper tubes d1 of the bank D and by the upper tubes11,1 of the bank N; that the side walls are cooled by the banks K andthe banks N and that the rear wall and baffle are cooled by the risertubes o, p, and by the downcomer pipesf and that the cooler water of thesystem is conducted from the steamand-water drum A through the bank F tothe lower header C whencevit is distributed through the pipes or tubesmi, m2, m3, m4 to the lower side wall headers M and to the bank J of thesteamgenerator section to the riser tubes o and p.

Thus in the circulatory system of the generator section and of the wallcooling section, thev direction of the flow of Water in all of the tubesexcept in the single `downwcomer bank F is upwardly. I'he large bank ofthe downcomer tubes, found in former constructions has been eliminated;the large mud drum of the old constructions has-also been eliminated;and space within the boiler walls is provided for the placement of theeconomizer, which most eiilciently abstracts the heat from the gasesleaving the boiler and transfers it to the incoming feed water. Thewater, delivered from the economizer to the steam-and-water drum is at ahigh steaming temperature because of the reduction in the area of theheating surface of the tubes of the steam generating section. I haveshown the front or fore wall Z1 of the furnace `chamber as being made ofrefractory material, but it is to be understood that this wallmay bewater-cooled in like manner when so desired. i

Having thus described my invention, what I claim and desire to protectby Letters Patent of the United States, is: A

1. In a boiler fory the combustion of nely divided fuel, the combinationwith a combustion chamber provided with a rearwall, of a relativelylarge steam-and-water drum at the top ofthe boiler in the rear portionthereof, a relatively small intermediate header at the front of theboiler and at a lowerlevel than said drum, a relatively small lowerheader at the bottom of 'said' boiler at the rear portion thereof, arelatively small bank of riser tubes exposed to the radiant heat in saidcombustion chamber and directly connecting said lower header with saidintermediate header, a bank of riser tubes exposed to the radiant heatof said combustion chamber directly connecting said front header withsaid steam-and-water drum, a plurality of banks of riser tubes'extendlngupwardly along said rear wall and directly connecting said lower headerwith said drum, onefof said banks o! tubes having the lower portionshielded from the radiant heatof the combustion ,chamber by said rearwall and another of' said banks being shielded from the radiant heat atthe upper portions thereof, and a relatively small bank of downcomertubes directly connecting saidl steam-andwater drum with said lowerheader and shielded from the radiant heat of the combustion cham- 2. Ina boiler for the combustion vided fuel, the combination with thecombustion chamber of a steam generating section and a wall of iinely'dicooling section, said generating section comprising a largesteam-and-water 'drum at the top of said boiler in the rear portionthereof, a relatively small intermediate header at the front of saidboiler and at a lower level than said drum, a relatively small lowerheader at the bottom of said boiler at the rear portion thereof, arelatively small bank of riser tubes connecting said lower header with.said intermediate header, a bank of riser tubes connecting saidintermediate header with said drum, and a relatively small bank ofdowncomer tubes connecting the lower side of said drum with said lowerheader and shielded from the direct radiant heat of said combustionchamber, said wall cooling section including a bank of `riser tubessubstantially covering the rear wall of said combustion chamber, saidriser tubes being shielded for portions ci their length and beingconnected at their upper ends directlyto said steam-and-water drum andconnected at their lower ends directly to said lower header, said wallcooling section also including banks of riser tubes covering the sidewalls and having their upper ends connected to said steam-and-water drumand having their lower endsconnected to said lower header, wherevby therelatively cooler water delivered from said steam-and-water drum to saidlower header, flows upwardly throughout the steam generating andthroughout the wall cooling sections from the lowest part of said boilerback to said steam-and-water drum.

3. In a boiler for the combination of finely divided fuel and the like,the combination with a combustion chamber of a steam generating section,a wall cooling section, and an economizer section, said generatingsection including a relatively large steam-and-water drum in the top ofthe boiler at the rear thereof, a relatively small intermediate headerat the front of said boiler at a lower level than the said drum, arelatively small lower mud header at the bottom of the said yboiler attherear portion thereof, a relatively small bank of riser tubesconnecting said lower header with said intermediate header and havingportions extending from the rear to the front in the upper portion ofthe combustion chamber, a bank of riser tubes connectirm saidintermediate header with said 4steam-,and-water drum and havingportionsshielded from the radiant heat of said combustion chamber; said wallcooling section including banks of riser tubes substantially coveringthe side walls of said combustion chamber, said riser tubes beingconnected at their upper ends to said Asteam-and-Water drum andconnected at their lower ends with said lower header, said wall coolingsection also including banks of riser tubes extending upwardly along therear wall of said combustion chamber, said riser tubes being connectedat their upper ends Vdirectly to said steam-and-water drum, andconnected at their lowerends directly to said lower header and havingportions shielded from the radiant heat o-f said combustion chainber,said economizer section being provided be-v neath said steam-and-waterdrum, and having riser 4tubes connected thereto, and a bank of downcomertubes connecting said steam-andwater drum and said lower header andshielded from the -radiant heat of said combustion chamber.

v4. In a boiler for the combustion of finely divided fuel and the like,the combination with a combustion chamber'of a steam generating section,and a wall cooling section, said generating section including arelatively large steam-andwater drum in the top of the boiler at therear thereof, a relatively small intermediate header at the front of.said boiler and below the level of the said drum, a relatively smalllower mud header at the bottom of the said boiler at the rear portionthereof, a relatively small bank of riser tubes connecting said lowerheader with said intermediate header and extending from the rear to thefront in the upper portion of the combustion chamber, a bank of risertubes connecting said intermediate header with said steam-and-Waterdrum, said wall cooling section including banks of riser tubessubstantially covering the side walls of said combustion chamber, saidriser tubes being connected at their upper ends to the steam-and-waterdrum and connected at their lower ends with said lower header, said wallcooling section also includingbanks of riser tubes extending upwardlyalong the rear wall of said combustion chamber, said riser tubes beingconnected at their upper-ends directly to said steam-and-water drum, andconnected at their lower ends directly to said lower header and havingportions shielded from the radiant heat of said combustion chamber, anda bank of downcomer tubes connecting said steam-andwater drum and saidlower header and shielded from the radiant heat of said combustioncharnber.

5. In a boiler for the combustion of finely divided fuel and the like,the combination with a combustion chamber of a steam generating section,a wall cooling section, an economizer section and a superheater, saidgenerating section including a relatively large steam-and-water drum inthe top of the boiler at the rear thereof,

a relatively small intermediate header at the front of said boiler at alower level than said drum, a relatively small lower mud header at thebottom of the said boiler at the rear portion thereof, a relativelysmall bank of staggered riser tubes connecting said lower header withsaid intermediate header, a bank of riser tubes connecting saidintermediate header with said steam-and-water drum having portionsshielded from the radiant heat of said combustion charnber, and a bankof downcomer tubes connecting the lower side of said steam-and-waterdrum with said lower header and shielded from the radiant heat of saidcombustion chamber, said wall cooling section including banks of risertubes substantially covering the side walls of said combustion chamber,s aid riser tubes being connected at their upper ends to saidsteam-andwater drum and connected at their lower ends with said lowerheader, said wall cooling section also including banks of riser tubesextending upwardlyralong the rear wall vof said combustion chamber, saidriser tubes being connected at their upper ends directly to saidsteam-and-water drum, and connected at their lower ends directly to saidlower header and having portions shielded from the radiant heat of saidcombustion chamber, said economizer section being provided beneath saidsteam-and-Water drum and having riser tubes connected thereto, saidsuperheater being relatively small and being positioned within saidcombustion chamber above the Vbank of riser tubes connecting the saidheaders

